Virtualization is a mechanism to share of some/all resources/capabilities in available in a computer system between multiple virtual machines (VMs) resident in the computer system. A VM is a software implementation of a machine (computer) that executes programs like a real machine.
In many computer systems that implement virtualization, a general purpose operating system (OS), such as Microsoft® Windows®, may run in a VM on one partition in the system. A general purpose OS, hereafter referred to as capability OS, a COS is an operating system that is independently capable of managing all resources on a computer system and providing all services to applications and lower level software. Certain functionalities in the computer system are critical to maintain operation even through a capability OS (COS) crash. One application that should be able to withstand a COS crash is a voice over internet protocol (VoIP) application. A VoIP application would benefit from this to allow a phone conversation to continue even through a COS crash. This would require the VoIP application to run outside of the capability OS partition.
As it becomes more common for different voice and audio applications to run in multiple VMs/partitions on computer systems, contentions for the use of audio peripherals in any given system may rise. In many instances there are multiple VMs with applications running on each VM that need access to the audio peripherals through a discrete audio codec. Additionally, in many of these systems, a discrete high definition (HD) audio codec chip operates in coordination with an audio controller chip to manage the use of audio peripherals in the system.